Coking coals are in short supply, that is why one of the most urgent problems of blast furnace production is to replace the coke by fuel mixtures based on noncoking coals, e.g. by coal-dust fuel whose resources are sufficiently large. With utilization of such fuel mixtures, it is especially important to provide for the uniformity of their supply to blast-furnace tuyeres.
Known in the art is a method of supplying coal-dust fuel to blast furnace tuyeres (see N. E. Dunayev et al., Vduvaniye pylevidnykh materialov v domennye pechi, Moscow, "Metallurgiya," 1977, p.p. 96-97), comprising transportation of the above fuel to conical dividers, dividing the fuel flow therewithin into a plurality of flows, the latter being directed along outgoing pipelines to the blast furnace tuyeres.
In the given case fuel is distributed to the tuyeres in a non-uniform manner because the values of hydraulic resistances of drain pipelines are different.
Also known in the art is a method of supplying pulverized fuel mixture, disclosed in the description of operation of the apparatus according to U.S. Pat. No. 3,204,942 and comprising batch loading a discharging chamber with a pulverized fuel mixture and subsequent continuous transportation thereof by means of carrier gas through calibrated openings of a distributor dividing the fuel flow into a plurality of flows, following which said mixture is supplied along outgoing pipelines to blast furnace tuyeres.
It is obvious that utilization of calibrated openings in the given method provides for equalization of the values of hydraulic pressures within the pipelines thereby improving uniformity of fuel distribution to the tuyeres. However, with oscillations of pressure at the blast furnace tuyeres and with wearing or stopping up at least one of the outgoing pipelines, the uniformity of fuel distribution to the tuyeres is upset. The above fact results in formation of conduits within the blast furnace shaft, in deterioration of descent of charge materials, i.e. in upsetting the optimum processing condition of the melting process.